PyroCMS: multiple navigation levels with changed navigation plugin (https://github.com/marcogrueter/pyrocms-professional/commit/ae67cce26ab2fc256d90d86bd22c882124bba472)

gistfile1.txt

<ul>
{{ navigation:links group="header" }}
  <li><a href="{{ url }}">{{ title }}</a>
	{{ if children_level_1 }}
	<ul>
	    {{ children_level_1 }}
			<li><a href="{{ url }}">{{ title }}</a>
			{{ if children_level_2 }}
		  		<ul>
		    		{{ children_level_2 }}
		      			<li><a href="{{ url }}">{{ title }}</a>
		      			{{ if children_level_3 }}
							<ul>
							    {{ children_level_3 }}
									<li><a href="{{ url }}">{{ title }}</a></li>
								{{ /children_level_3 }}
							</ul>
						{{ endif }}
						</li>
					{{ /children_level_2 }}
				</ul>
			{{ endif }}
			</li>
		{{ /children_level_1 }}
	</ul>
	{{ endif }}
	</li>
{{ /navigation:links }}
</ul>